This invention relates to gas-cushion vehicles which are also referred to as surface-effect ships, wherein the ship rides on a cushion of air permitting the ship to cruise at a higher speed by reducing the resistance to its movement.
The preferred form of this invention is directed to surface-effect ships that have fixed side walls with flexible skirts or seals fore and aft although such invention is also applicable to where the skirt bounds the entire lower periphery of the vehicle. The side walls cooperate with the skirts to contain the air bubble and act as a keel to give the vehicle greater lateral stability in water. The invention is equally applicable to land vehicles.
In operating vehicles on gas-cushion principles, it is important to provide skirts that are flexible and able to withstand the tremendous impact forces encountered when traversing waves or projections and depressions in the case of land vehicles. The present invention provides a novel suspension system for maintaining the flexible skirt in position, while permitting it to be made of light-weight material and permitting it maximum resiliency. When building ships employing the surface-effect or gas-cushion principle, the carrying capacities have been limited because the skirts which provide the containment of the air cushion must be of adequate strength to withstand the forces developed both internally and externally. By the mere scaling up of existing designs as an example of from a 100 ton to a 2,000 ton vehicle, the strength of the coated fabric materials scales up to a 11,000 pounds tensile per inch of width and the weight of the coated fabric material is estimated to exceed 75 tons. Fabric material in this strength range are not readily available and the processing of such massive structures becomes a major problem. In addition, the seams employed for such fabric material would become cumbersome and extensive to further complicate the problem of weight, processing and fabrication.
The present invention overcomes these difficulties by providing a new and improved construction for the skirt assemblies, wherein the skirt of elastomeric coated fabric membrane or material is supported from the main frame of the vehicle by a plurality of cable-like or belt-like high strength members arranged in vertical planes, which members are the primary load-bearing members of the skirt structure enabling the use of lightweight material since the construction permits a reduction in fabric strength.